1. Field of the Invention
This invention relates to a mining machine, and more particularly, to a mining machine that includes a mining machine frame having a plurality of pivots for a boom assembly and for piston cylinder assemblies with the piston cylinder assemblies being positioned selectively at the respective pivot points to provide mining machine boom assemblies having different cutting heights which may be utilized with the same continuous mining machine.
2. Description of the Prior Art
It is well known in underground mining to provide mining machines with adjustable cutting means and pivotally secured boom assemblies movable by means of pivotally secured piston cylinder assemblies.
U.S. Pat. No. 2,282,704 discloses a vehicle for gathering and carrying mined material and having a detachable loading head. The detachable loading head is laterally movable on the main frame of the vehicle, and is secured to the vehicle by upwardly projecting apertured brackets on a platform supporting the gathering head to which apertured arms are pivotally connected to the loading head by pins.
U.S. Pat. No. 2,866,626 discloses a mining machine having two rows of cutter heads hydraulically movable on a vertical axis away from each other and inclinable relative to the axis of the frame carrying the cutting heads, and being supported on a boom assembly which is vertically movable relative to the axis of the mining machine frame.
U.S Pat. No. 2,868,531 discloses a cutter head for a mining machine having an adjustable cusp cutter.
U.S. Pat. No. 3,013,784 discloses a mining machine having an adjustable head mechanism movable in the vertical and horizontal planes. Gearing allows for movement of the cutter head around the axis of the drive shaft while the cutter head rotates.
U.S. Pat. No. 3,208,797 discloses a continuous mining machine having a cutter frame structure supported on three points, two of which points are cylinders mounted on either side of the cutter frame with pistons having balls fitting into sockets, and the third point being an universal joint. The cutter frame structure is adjustable with respect to the vertical and transverse longitudinal axes of the mining machine frame.
U.S. Pat. Nos. 3,730,593 and 3,774,969 as well as 3,848,930 and 4,056,189 disclose a boom member pivotally connected to the frame of a continuous mining machine by means of rearwardly extending parallel arm members. The arm members are pivotally connected to a piston rod of a piston cylinder assembly which is pivotally connected at its other end to the mining machine frame. Retraction of the piston rod of the piston cylinder assembly pivots the boom member vertically about the pivot point of the arms connected to the boom member.
U.S. Pat. No. 4,076,316 discloses a boom member pivotally connected to the frame of the mining machine by means of arm members. A pair of parallel support members are positioned laterally of the boom arm members and extend forwardly therefrom. The support members are supported on cylindrical members which extend laterally from the ar members and whose rearward end portions have a cylindrical recess arranged to receive the cylindrical members to allow the support members to move laterally toward and away from the arm members.
U.S. Pat. No. 4,088,371 discloses a continuous mining machine with a forwardly extending boom member having parallel rearwardly extending arm members which are pivotally connected to the mining machine frame. A piston rod of a piston cylinder assembly is pivotally connected to the arm members and the other end of the piston cylinder assembly is pivotally connected to the mining machine frame. Extension and retraction of the piston rod effects vertical movement of the boom member around the pivot point of the boom member.
There are other examples in the prior art of a boom member pivotally secured to the mining machine frame of a continuous mining machine, and movable relative to the mining machine frame around the pivot point of the boom assembly by means of a piston cylinder assembly pivotally connected to the boom member and also pivotally connected to the mining machine. Recent examples of this type of boom assembly for a continuous mining machine may be seen in U.S. Pat. No 4,641,888 and U.S. Pat. No. 4,582,363.
Although the prior art discloses adjustable cutter frame assemblies, and pivotally secured boom assemblies movable about a vertical plane by means of pivotally secured piston cylinder assemblies, there remains a need for a boom assembly having interchangeably functional dual pivot points for receiving either the boom assembly structure pivotally thereon, or a piston cylinder assembly pivotally thereon to enable the continuous mining machine frame assembly to accomodate either a relatively low cutting height boom assembly or a relatively higher cutting height boom assembly.